apparently Grant He added such entries to the string base by hand (something which Patrick Belley also seems to be doing. Those strings will be wiped out if you do an automatic update using poedit and the xgettext script that it calls.

if you look though the code in ContentGenerator.pm for printing out the instructor links you'll see that some entries have an explicit text => $r->maketext("library browser") type tag and others (probably older entries such as Statistics) don't have this option. Here the link text is generated automatically. "Statistics" is in the source language file (.pot) but it never appears in a maketext() statement so it is not found by xget

heiderich has added a bunch of maketext() to the webwork2 side, and I think some to the pg side but I haven't checked that. He wants to keep the german translating dictionary private for the moment -- I think I forwarded an email to you about that.

I think that MathBox and Three.js are still great, but writing WeBWorK macros for them may be more work for us and creating interactive 3D graphics using them may (or may not) be easy for problem authors.